In modern mobile communication systems different mobile radio standards like Universal Mobile Telecommunications System (UMTS), Wideband Code Division Multiple Access (WCDMA), Global System for Mobile communication (GSM), and enhanced data rates for GSM evolution (EDGE) are used. Thereby the GSM standard is often referenced as second generation standard (2G), EDGE is referenced as a standard of generation 2.5 (2.5G) and UMTS is referenced as a third generation standard (3G).
Respective radio frequency (RF) signals are received and processed in a radio frequency unit which may be used for down converting the radio frequency signals to base band (BB) signals. Such radio frequency units are in many cases implemented in an integrated circuit. The data received by the radio frequency unit from an antenna are converted to digital signals which are transmitted to a base band unit for further processing. A function of the radio frequency unit can be controlled by the base band unit. It is furthermore possible that an interface between the radio frequency unit and the base band unit is realized as a interface. Such an interface is not restricted to transmit received (RX) data from a radio frequency unit to a base band unit but also to transmit data to be transmitted (TX) via a radio frequency unit between the base band unit and the radio frequency unit.
Respective base band units and radio frequency units can be able to operate within the GSM/EDGE standard or the UMTS standard or both the GSM/EDGE and the UMTS standard. In other words, various combinations of 2.5G mobile radio standards and 3G mobile communication standards are possible. A GSM/EDGE standard is also referenced as an enhanced general packet radio service (EGPRS).
When transmitting data over the interface between the radio frequency unit and the base band unit, it is possible that a time base for the transmitted data is defined and adhered to.